Safety device for pressure systems



W. C. DENNIS SAFETY DEVICE FOR PRESSURE SYSTEMS March 7, 1933.

Filed May 27, 1929 l @l a l w1 I m9 Zeu.

4 Woman,

Patented Mar. 7, 1933 UNITED STATES WILLIAM c. nmnrrs, or MILWAUKEE,

PROCESS COMORATION, OF MILWAUKEE, WISCONSIN,

CONSIN 'application mea lay a7,

The invention relates to safety devices for pressure systems where steam, water, air, oil or other fluids are used at high pressure.

One of the objects of the invention is to 151 provide a simple, positive and 'reliable apparatus for automatically limiting the pressure in the 'pressure system` to any desired degree.

A furthervobject of the invention is to pro,

er conclusion hereof.

In the drawing tional view through a safety device embodyin the invention; ig.` 2 isla-plan view of the device with the cover cap removed;

Fig. 3 is a diagrammatic v iew of a presv sure system in .connection with lwhich the device may be used. Referring to the drawing the numeral 5V designates a casing which ma be part of a pressure pump body or a fitting in a pressure line in which the pressure fluid is conducted by a pipe 6 to a passage 7.

A valve vseat member 8 is removabl fitted into a bore 9 communicating with t e passage 7 with a suitable sealing lgasket 10 interposed between it and a seat 11 and is firmly held against its seat 12 by a tubular plug 13 havin threaded engagement with the threa ed portion of the bore 9. The seat member has a Abore 14 extending therethrough and preferably a conically-shaped seat 15 at its outer end.

A needle or poppet valve 16 lis fitted to slide freely in the bore of the plug 13 and is provided with longitudinally extending grooves 17 for the ready passage of the 'pressure fluid to a chamber 18.

A housing membe 19 is securely'mounted u on the casing 5'by bolts 20 and contains all 5 ci) the valve operating or controlling'mecha-A Fig. 1 is va vertical sec-v WISCONSIN, ASSIGNOR TO CLLYBOU'RN L. CORPORATION 0F WIB- .SAFETY DEVICE FCB PRESSURE SYS'l'liiISy 192s. semi 1ro. escasa.

nism. This housing is provided with a bore 21 communicating with the chamber 18 and having a by-pass or overflow passage 22 leading therefrom.

A spring seat plu 23 is slidabl mounted 55 in the housing mem r 19 and is lield in en agement with the stem of the valve 16 by a heavy spring 24 interposed between said plug and a spring seat plug 25. Pressure is placed on the spring 24 by a screw plug 26 so which is ladjustably mounted'in thev reduced threaded bore 27 in said housing and engages the plug-25.

The plug 23 has passages28 therein for the ready passage of pressure iiuid past said plug e5 and the plug 26 has a wrench-engaging portion or polygonal end 29 andis held in adjusted position by a locknut 30.- The end 29 and nut 30 are located above the upper end.

lof the-housing so that they are readily accessible for adjustment.

With this construction the tension ofthe y spring 24 is set to hold. the valve 16 'closed\ under all normal working pressure conditions in the pressure system. When, however, this pressure is exceeded the excess pressure overcomes the action of the spring 24 and lifts `the valve 16 and allows the pressure fluid to escape from the system, thereb reducing the pressure in the system and t ereby, in most cases, overcoming any danger or possible damage incident to such excessive pressures.

However, to further insure against damage due to excessive pressure the device is proi vided with a safety electric control. For this purpose the plugs 25 and 26 have alined bores 31 and 32y in which a rod 33, bearing at its lower end on the plug 23, is mounted. This rod extends upwardly through a block 34 oi`- 90 insulating material secured to a supporting sleeve 35 having threaded engagement at 36 with the housing and ab'uts against a block' or button 37 of insulating material movably mounted in a recess 38 in said block 34.

A spring contact 39 is secured to the block 34 by a terminal screw 40 and its free end extends over the button 37. A spring contact 41 is secured to the block 34 adjacent a washer 42 by a terminal screw 43 and its free 100 'auf end extends over the free endvof the contact 41 and in the path of movement thereof.' Y

With this arrangement -when the valve -16 is lifted, as previously described, the plug 23 and rod 33 are likewise lifted and the rod 33 thus moves the button 37 outwardly together with the free end of the Contact 39 which thus moves into'circuit closing relation with the contact 41 .and thus closes a control circuit that operates, for example, as shown in Fig. 3,- a coil 45 of a relay switch 46 whiehthus opens this switch and thereby opens the power circuit of a motor 47 which is supplying the power for driving the pump 48, thus stopping said motor and any further action of the pump. A top cover 49 has a sliding 't on'the J block 34. Y

i I desire it to be understood that this invenas such limitations are included in the claim.

What I claim as my invention is In a safety device for pressure systems, the.

combination with a pressure line, of a casing provided with a valve-controlled vrelief passa e, a needle valve controlling said passage,

a ousing secured to said casing, a sprlng y engaging said 'ot mounted in said housing, spring seat plugs engaged by said spring, one of said plugs engaging said valve, a tensionfadjusting plug in threaded engagment with said casing and er spring seat plug, said 1ast-named plug and tension adjusting plu having alined bores, a switch-operating r passingthrough said bores and engaging said other spring seat plug, said rod also projectin beyond the caslng.

testimony whereof, I aix mly'si ature.

' Y WILLIAM (l.` E

tion is not to be limited to any particular orm or arrangement of parts except in so far 

